Link chain having electrical conducting lacquer piercing ridges



Aug. 16, 1966 T. ROSENBERG 3,267,203

LINK CHAIN HAVING ELECTRICAL CONDUCTING LACQUER PIERCING RIDGES Filed Aug. 23, 1965 FIG. 4

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r I I 30 q I| INVENTOR .J THOMAS ROSENBERG PRIOR ART United States Patent LINK CHAIN HAVING ELECTRICAL CONDUCT- ING LACQUER. PIERCING RIDGES Thomas Rosenberg, Mount Vernon, N.Y;, assignor to Eastern Chain Works, 1110., New York, N.Y.

Filed Aug. 23, 1965, Ser. No. 481,547 1 Claim. (Cl. 17468) The present invention relates to a chain construction, and particularly to a chain that is electrically conductive and normally grounded.

A primary object of the present invention is to provide a chain for lamps and the like which will conduct electricity so that the chain will conform to and be in compliance with various regulations, such as those promulgated by the Underwriters Laboratories, Inc.

Another object is to provide such an electrically conducting chain which includes links that each have one or more ridges or sharp pointed portions on their inner end portions whereby these sharp pointed portions or ridges will penetrate through the lacquer or coating on the chain links to thereby make the links electrically conductive and hence automatically provides a means for grounding the chain.

Another object is toprovide such a chain construction that is adapted to minimize errors productive of wasted labor and material in the formation thereof.

Further objects and advantages are to provide improved elements and arrangements thereof in a device that is economical to produce, durable in form, and conducive to the most economical use of materials and uniformity 'of members formed therefrom.

Still further objects, and advantages will become apparent in the subsequent description in the specification.

In the drawings:

FIG. 1 is a perspective view illustrating the chain of the present invention in use.

FIG. 2 is a perspective view of the chain per se.

FIG. 3 is a further enlarged fragmentary sectional view illustrating the present invention.

FIG. 4 is an enlarged sectional view taken on line 4-4 of FIG. 3.

FIG. 5 is a view generally similar to FIG. 4 but showing the prior art type of chain.

Referring in detail to the drawings, the numeral 20 indicates the chain constructed according to the present invention, as shown in FIG. 1, and the chain 20 can be used for any desired purpose and for a fixture such as a lamp 21 suspended or connected to the lower end of the chain 20. The upper end of the chain can be connected to any type of supporting structure 22 which may be a ceiling or the like. As shown in FIG. 2 for example, the chain 20 includes or comprises a plurality of similar links 23 which are interfitted or interconnected together, and links 23 are adapted to be made of a suitable material, such as a suitable metal that conducts electricity.

Each of the links 23 include spaced apart side portions 24 as well as diametrically disposed end portions 25. The links 23 have a generally oval formation or construction.

The numeral 27 indicates a coating of material such as lacquer which encloses or surrounds the metal links 23, as for example, to protect the finish of the links. This lacquer or coating 27 makes the links of an insulating nature, but due to recent changes in the pertinent regulations or laws, such as those set out by the Underwriters Laboratories, Inc., it is necessary in certain instances that such chains be grounded and electrically conductive. According to the present invention, this is accomplished in a highly economical and novel manner by providing on the inner surfaces of the end portion 25 a plurality of 3,267,203 Patented August 1.6,. 1966 ice I sharp tapered ridges or pointed portions 28 which are arranged and shaped so that they will penetrate the lacquer 27 and therefore establish electrical communication be tween the links so that the chain will be in conformity and compliance with the pertinent regulations of the Underwriters Laboratories, Inc. In addition these ridges or pointed portions 28 are only arranged on the inner surfaces of the interfitting portions 25 so that these ridges are not normally visible to the eye whereby there will be nothing to detract from the aesthetic appearance of the chain. The pointed ridges 28 will penetrate through the insulating lacquer 27 whenever a sufficient weight is suspended from the chain 20 as, for example, when a weighted member, such as the fixture 21 is suspended from the chain. In addition, the normal slightly swinging movement of the fixture and chain will help insure that the pointed prongs or ridges 28 will penetrate through the insulated lacquer 27 to cause the entire chain to be grounded and electrically conductive.

Attention is directed to FIG. 5 of the drawings wherein the numeral 29 indicates a portion of a prior art type of chain which does not have the means of the present invention for penetrating through the lacquer. Thus, in FIG. 5 the chain 29 has links 30 having the adjacent end portions 31 that correspond to the end portions 25 and the links 30 also have the lacquer 32 thereon which corresponds to the previously described lacquer 27. However, it will be noted that in FIG. 5 there are no pointed edges or ridges 28, and hence the lacquer 32 serves to provide a barrier or layer of insulation between adjacent links so that the chain is not automatically conductive or self-grounded as is the case with the chain 20 constructed in accordance with the present invention.

From the foregoing, it will be seen that there has been provided an improved link chain construction which will accomplish the purposes desired.

It will now be clear that there is provided a device which accomplishes the objectives heretofore set forth. While the invention has been disclosed in its preferred form, it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claim.

I claim:

A vertically disposed conducting chain that normally does not transmit current except when a fixture would create a dangerous condition due to a fraying of an electrical wire which would come in contact with the device to give a shock, embodying a plurality of similar metal links interconnected together, each of said links having a full coating of hardened lacquer finish thereon so that the entire chain has a full coating of lacquer finish as insulation and normally insulating the chain, said chain being adapted to be suspended from a structure and adapted to have a fixture on the lower end thereof, each of the links having diametrically arcuate end portions, the inner surfaces only of the arcuate end portions being provided with a plurality of sharp tapered pointed ridges wherein the lacquer in the vicinity of the ridges is penetrated and pierced by the ridges so that the same is electrically conductive throughout its length, the remaining portion of the links having the lacquer thereon except where the ridges engage each other, said ridges being arranged in spaced apart relation with respect to each other, and whereby movement of the chain increases the electrical contact between the ridges, said ridges increasing the strength of the chain, and being arranged so that the ridges are only on the inner surfaces of the diametrically 3,267,203 3 4 arcuate end portions with the remainder of the links being References Cited by the Examiner free of ridges, said ridges being arranged in spaced parallel UNITED STATES PATENTS relation to each other, and said ridges having a longitudinal axis extending transversely to the plane of the links, 225O280 7/1941 Starblrd' and said adjacent links being arranged at angles with 2580321 12/1951 Rees 174-35 X respect to each other, whereby the ridges of one link F EI N PATENTS engage and are at right angles with respect to the ridges 599 432 6/19 0 Canada the adjacent LARAMIE E. ASKIN, Primary Examiner. 

